PHP : strpos recursive function

strpos.php

<?php
$mystring = 'welcome !! we are learning now string function';
$findme   = 'learning';
$pos = strpos($mystring, $findme);


if ($pos === false) {
    echo "The string '$findme' was not found in the string '$mystring'";
} else {
    echo "The string '$findme' was found in the string '$mystring'"."\n";
    echo " and exists at position $pos";
}

?>

<?php
function strpos_recursive($haystack, $needle, $offset = 0, &$results = array()) {                
    $offset = strpos($haystack, $needle, $offset);
    if($offset === false) {
        return $results;            
    } else {
        $results[] = $offset;
        return strpos_recursive($haystack, $needle, ($offset + 1), $results);
    }
}
?>
<br>

<?php
$search = 'a';
$found = strpos_recursive($mystring, $search);

if($found) {
    foreach($found as $pos) {
        echo 'Found "'.$search.'" in string "'.$mystring.'" at position <b>'.$pos.'</b><br />';
    }    
} else {
    echo '"'.$search.'" not found in "'.$mystring.'"';
}
?>

On line 23
+1 should be strlen($needle)